# Statistics - Variation and Standard Deviation

A population of scores has μ = 20 and σ = 5. If every score in the population is multiplied by 2, then the new values for the mean and standard deviation would be:

standard deviation = _______________

A sample of scores has M = 30 and s = 10. If 3 points are added to every score in the population, then the new values for the mean and standard deviation would be:

standard deviation = _______________

A developmental psychologist studies the number of words seven infants have learned at a particular age. Find the mean, SS, variance, and standard deviation of the number of words learned by this POPULATION of infants.

X f

--------------------

9 2

8 3

7 4

6 1

5 3

4 5

3 0

2 1

1 2

0 4

SS:_______________________

Variance:_______________________

Standard Deviation:_______________________

What would the standard deviation be if this were a sample?

#### Solution Summary

Complete, Neat and Step-by-step Solutions are provided. Also attached Excel file for Solution.